This invention relates to a method of dicing a semiconductor wafer.
With most semiconductor products, for example, transistors, diodes, light emitting diodes, and integrated circuits, a large number of elements are manufactured simultaneously on a large semiconductor wafer of Si, GaP, GaAs, saphire, etc. The semiconductor industry employs the term "dicing technologies" to refer to those techniques for obtaining a large number of high quality pellets from each semiconductor wafer. Two dicing methods are particularly well known in the art. These are the grinding-cutting method, using a blade or wire saw, and the scribing method, using a diamond point. When laying out the pattern of pellets on the surface of the semiconductor wafer, the distance between adjacent pellets has been minimized to maximize efficiency.
However, three restrictions exist with respect to the minimum distance permissible between adjacent pellets. The first restriction is the actual dicing width, the second restriction is the degree of precision to which the cutting machine can be adjusted, and the third restriction is the cracks and chips extending horizontally from the dicing line. Of these restrictions, the third, namely the generation of cracks and chips, creates the most significant limitation with respect to minimizing the distance between adjacent pellets.
FIG. 1(a) illustrates the product of the traditional grinding-cutting method, and FIG. 1(b) illustrates the product of the traditional scribing method. Similar elements in these FIGURES are assigned the same reference numbers. A semiconductor substrate 11 carries many active element areas such as 12, 13 (not shown in detail), and dicing occurs in the space between the adjacent active element areas 12, 13. Many cracks and chips 14 are generated horizontally from a dicing line 15. Therefore, the distance between active element areas 12, 13 (shown in FIGS. 1(a) and 1(b) as distance A--A) has to be 100-200 .mu.m to prevent the active element areas 12, 13 from being influenced by cracks and chips 14.